feat: support reopening of issues and other state changes

[ParadauxIO]

Hi there, love that this now exists -- I've been wanting a youtrack integration forever but never got around to implementing my own. There doesn't appear to be a workflow trigger when state changes, such as resolved - re-opened. Is this fixable or a limitation of the workflow API?

[TomDotBat]

I wouldn't call this unintended behaviour, just simply missed out from implementation due to the project's needs at the time.

I believe this is something that can be easily added, but we could do with the refactor (#2) before implementing this.